The length of the first side of the triangle is 6 meters. The length is 2 times longer than the length of the first.

The length of the first side of the triangle is 6 meters. The length is 2 times longer than the length of the first. A third side is 3 meters shorter. Find the length of the third side. Find the perimeter of this triangle.

To find the third side of a triangle, we first need to find the second side of the triangle.

If the first side of the triangle is 6 meters, and the second is 2 times longer than the first side, then we need:

6 * 2 = 12,

And the third side is 3 meters shorter than the second, which means we need:

12 – 3 = 9.

Now we will find the perimeter of this triangle, the perimeter is the sum of all sides.

6 + 12 = 18;

18 + 9 = 27.

Answer: The third side of the triangle is 27 meters, and the perimeter of this triangle is 27 meters.